Researchers have retracted a systematic review that suggested that antipsychotic drugs are effective and safe for patients with symptoms of dementia — but claim their re-analysis of the updated data still comes to the same conclusions.

According to the retraction notice in Alzheimer’s Research and Therapy, some participants were incorrectly included twice in the meta-analysis.

The corresponding authors recently lost another paper for an entirely different reason — earlier this year, we reported on a retraction in Annals of Neurology for Jin-Tai Yu and Lan Tan, affiliated with the Ocean University of China, Qingdao University, and Nanjing Medical University in China. The authors pulled that paperafter appearing to pass off others’ data as their own.

This article has been retracted by the authors after discovering an error in the data. The two CATIE-AD articles included in the systematic review [1, 2] should not have been treated as separate trials as this led to data from some trial participants being included twice in the meta-analysis. As a result, large sections of the article are inaccurate. To avoid confusion this article has been retracted and the authors have been given the opportunity to resubmit their corrected data.

Yu told us a reader initially spotted the error. Here’s how the authors addressed it:

As the Sultzer et al 2008 paper did not report [adverse effects] because of the design in its sub-analysis, we decided to delete the Sultzer et al 2008 paper and only included the data from Schneider et al 2006 that they used was completer data over 12 weeks. Although some data changed after deleting the Sultzer et al 2008 paper, the conclusions remain the same.

Yu added:

The corrected data showed the same trends as the original conclusions.

The original study reported:

Aripiprazole and risperidone are able to improve psychiatric symptoms and slow decline in cognition function at average 12 weeks in patients with neuropsychiatric symptoms of dementia. However, high adverse events may offset the efficacy of atypical antipsychotics in dementia.